Downlink Power Minimization in Intelligent Reflecting Surface Aided Security Classification Wireless Communications System

User privacy protection is considered a critical issue in wireless networks, which drives the demand for various secure information interaction techniques. In this paper, we introduce an intelligent reflecting surface (IRS)-aided security classification communication system, reduces transmit power of base station (BS) by classifying users with different requirements. Specifically, divide into confidential subscribers requirements and general simple During period, guarantee rate while ensuring service quality users, thereby reducing BS. To realize such green transmission, BS implements beamforming design on transmitted signal superimposed artificial noise (AN) then broadcasts it to assistance IRS's reflection. We develop alternating optimization framework minimize downlink respect active beamformers BS, AN vector at reflection phase shifts IRS. A successive convex approximation (SCA) method proposed so that nonconvex problems can be converted tractable forms. The simulation results demonstrate algorithm convergent reduce 20\% compared best benchmark scheme.